New series of power management ICs for energy harvesting 
Optimizing charge and discharge of rechargeable batteries in remote controls, IoT sensors, Bluetooth^® trackers, etc.

Equipped with AKM’s proprietary ultra-low current voltage monitoring system, the AP4413 series enables autonomous charging of a small rechargeable battery via energy harvesting, which is becoming increasingly common across a wide range of applications such as remote controls, Bluetooth® trackers, and IoT sensors, which have traditionally used disposable batteries. 

This is particularly relevant in Europe, where the transition to rechargeable batteries is being promoted by Regulation (EU) 2023/1542 to evaluate the feasibility of phasing out disposable batteries.²

AKM has accumulated wide-ranging expertise in product technology and applications through the development and mass production of PMICs for energy harvesting. These devices allow system designers to utilize small amounts of ambient environmental energy, such as indoor light and body heat, to operate a variety of electronic devices, many of which are battery-operated. This is especially beneficial for IoT environmental sensors such as CO2 monitors that are installed in locations where line power is not easily accessible, and where battery replacement would be difficult.

Using energy harvesting to charge batteries is challenging, because the harvested voltage and current tend to be small and often unstable. It is therefore essential to minimize the PMIC’s power consumption and prevent excessive charging and discharging. The AP4413 series’ ultra-low 52 nA current consumption has minimal impact on a system’s power budget, and its voltage monitoring system prevents rechargeable batteries from becoming completely discharged, allowing for quick startup and/or recovery. Furthermore, the addition of an inline capacitor (see figure 2) allows the AP4413 series PMICs to support system operation even when the battery is completely discharged, while recharging it at the same time.